1. Technical Field
This invention relates to detection systems and, more particularly, to an automated detection system for sports fields and the like.
2. Prior Art
In basketball, like many other sporting events having boundaries of play, judgment calls must be made continually as to whether events have taken place “in” or “out” of the boundary. Since the game play occurs at a rather rapid speed and the basketball is often obscured by the player's body, such judgment calls are extremely difficult because of the inherent inability of the human eye to follow an object moving at such a speed, and relate the relative position of impact on or over a line.
Prior to this time, a number of devices have been proposed which replace human judgment with a mechanical or optical sensor. The shortcomings of these devices, however, have prevented the widespread acceptance of any of these devices. Many of the previous devices require modification of the ball to plot its position relative to electrical conductors provided beneath the court and or its boundaries. This may be unacceptable in regulation play, and greatly increases the cost of basketballs and of modifying existing courts.
A second type of device is one which is laid on the playing surface and senses the impact of the ball or player on the critical boundary. These sensors are made of materials that are not well suited to withstand the strain of multiple impacts over a long period of time. One example shows a pressure switch, known as a “membrane” switch, which is comprised of foil conductors separated by a dielectric with holes. The weight of the impact presses the foil together within holes formed in the dielectric material.
The switches depend on plastic deformation of the conductors. Repeated deformations of this type, particularly under heavy pressure, tend to stretch the conductors, which over time may cause an electrical failure. Typically, the onset of failure is indicated by intermittent or multiple switching contacts per actual impact on the sensing device. This unreliability over time is unacceptable. Finally, a serious problem is “shadowing.” This is the masking of one impact by another. For example, if a foot is already on the line when the ball hits, the sensor must be able to still detect the second impact, even if the two events are quite close together or simultaneous.
Accordingly, a need remains for an automated detection system for sports fields and the like in order to overcome the above-noted shortcomings. The present invention satisfies such a need by providing a detection system that is automatic in design, provides accurate pressure measurements and allows for improved flow and regulation of a game. Such a system automatically detects if a basketball player's foot or the basketball itself has touched the sideline or end-line markings of a basketball court. This allows game officials to referee a game more accurately, as well as reduce the instances of incorrect calls, which results in a more fair and balanced game between the opposing teams. Such a system thus also reduces the frequency of debates and heated arguments between players, coaches and the officials regarding questionable calls. The detection system can easily be incorporated to assist referees in sports other than basketball, like baseball, football and tennis, to name a few.